The monarch is reportedly seeking to generate commercial revenue from the mansion after removing the Duke of York, who is currently refusing to leave.
Andrew has turned down other homes on offer and is relying on a “cast-iron lease” that stipulates he must keep the dilapidated £30m lodge in Windsor Great Park in good condition.
But sources say Charles will succeed in getting Andrew to leave, with speculation that he may even cut off the £4 million a year support he gives him.
“It makes sense for the Royal Lodge to be handed back to the Crown Estates, who can then pay for much-needed repairs and refurbishments,” the insider said.
“Then it can be rented out to make money for them, for the King’s coffers and for the country, rather than wasting everyone’s resources.”
One real estate expert said: “For a house of this size with such enormous royal connections, a rent of £1 million a year is not at all unreasonable.”